Process for producing sound films and matrix therefor



Feb. 24, 1942. H. WESTERKAMP 2,

PROCESS FOR PRODUCING scum: FILMS AND MATRIX THEREFOR Filed May 14, 1940 Fig.3

Patented Feb. 24, 1942 PROCESS FOR PRODUCING SOUND FILMS AND MATRIX THEREFOR Hugo Westerkamp,Cologne-Braunsteld, Germany Application my 14, 1940, Serial No. 335,194 Germany June 28, 1939 Claims. (Cl. iii-5.3)

The invention relates to a process for producing sound films with mechanical sound recording by pressing a ribbon-shaped matrix on a rib+ bon capable of being pressed, and to a pressing matrix for carrying out'this process.

The object of the invention is to reduce the quantity of the material required for producing sound films to a small amount, particularly also in the case of sound films produced'by means of a pressing matrix with lateral guideridges.

For this purpose, the invention provides continuous pressing of the matrix on a ribbon whose width exceeds that of the sound track area, at the same time cutting of! the margin of the ribbon outside the sound track area by means of ribs on the matrix extending along the sound record. In using a pressing matrix with lateral guide ridges, theinvention furthermore provides ior dimensioning these ridges so as tosimultaneously fulfill the function or the ribs of cutting the margins of the pressed films.

I In this respect it is observed that it is known in producing gramophonelrecords by means of a pressingfmatrix to provide the circular matrix at its circumierence with a rib for limiting the circumierenc'e oi the gramophonerecord. Such matrices are, however, merely used for producing gramophone records from a iormless material placed below the pressing matrix which is flattened by the pressure exerted, the material flowing irregularly from-the centre of the pressing matrix to its edge and beyond this edg thus not only thickening this edge but also giving it a duiteirregular shape. The outer rib or they pressing matrix in the present case serves to produce a circular with a smooth edge, whereas the rib does; not, as in the case or the process according tothe invention, serve to cut a sound carrier havinga. smooth edge merely for the pur- Dose oiisavingmaterial, considering also that in the case or the mentioned production oi gramophone records no considerable saving or material to the invention and the production of pressed is eflected, the discs neither being provided from the beginning with a broad unrecorded margin nor requiring such a margin, whereas theproduction of. perlectly reproducible sound ribbons by pressing with a ribbon-shaped matrix is only possible it the width oithe unrecorded sound ribbon exceeds that of the sound track area to. such a degree that the unrecorded marginal zones amount to nearly hall the width ribbon being'pressed. a

A ribbon-shaped pressing matrix according to of the entire the invention is provided, on both sides or the,

sound track area, with preierably knife-shaped ribs running in longitudinal direction ofthe ribbon and having a height equal to or greater than the'thickness of the films to be pressed. Preferably, the ribs are shaped so as to be steep towards the sound tracks, thus serving at the same known manner a galvanoplastic coating on the original record.

The drawing illustrates by way of examples the production of a pressing matrix according films with the aid of such a matrix. I Fig. 1 is a section through a recorded original wax ribbon and a matrix corresponding to this ribbon.

- Fig. 2 is a corresponding view of a modified arrangement. 1

Fig. 3 shows the pressing of the matrix into an impressible ribbon.

Fig. 4 is a conventional showing of the apparatus for pressing the matrix into a ribbon. Fig. 5 is a transverse sectional view showing the employment of the guiding gauge in Fig. 4.

The wax ribbon l consists of a carrier 2 with a wax layer 3 thereon. This wax layer bears the sound tracks 4 cut into it. Parallel to the edges of the sound ribbon on either side of the sound track area runs a guide groove 5 whose depth is greater than that of the sound tracks. Between the guide groove 5 and the sound tracks 4 there is another groove 6 parallel to both edges or the sound ribbon. The depth or this groove 3 is greater than that or the groove 5, the cutting depth of the groove i being equal to or greater than the thickness of the iilms to be pressed.

The surface or the sound ribbon with the sound tracks I and the grooves 6 and 6 is next provided with a conductive coating, for example bath. This matrix has then in its central portion the sound tracks l and on either side or 'these tracks 0! guide ridge 6 and a. rib 6. The guide ridges 5 serve for guiding the matrix ribbon in pressing the sound him copy, whereas the ribs 6 cut the pressed copy at the sides.

Instead of providing a matrix with guide ridges i and ribs 6, it is also possible to give the ridges b the shape of ribs for cutting the film copy. Fig. 2 shows an original sound record ribbon I film copy.

there are out two deep grooves 8, the depth again being equal to or greater than the thickness of the films to be pressed. The surface I of the groove adjacent to the sound tracks 4 is perpendicular or nearly perpendicular to the surrace 01 the film.

. In Fig. 2, the matrixproduced by means of such an original sound ribbon, for example, in

the manner described above, is marked ll. Jitter being removed from the original sound record ribbon, the matrix is used for pressing the sound This pressing is illustrated diagrammatically in Fig. 3, in which it signifies the pressing matrix and II the film to be pressed. The matrix ribbon, illustrated by way of example in Fig. 4, is passed together with the ribbon to be pressed between two pressing rollers i2 and I3, 80 that,

the matrix and impressible ribbon advance longitudinally together at the same rate; there being arranged gauges l4 before and behind the rollers for guiding the matrix ribbon. These gauges are illustrated in cross section in Fig. 5; the lateral guiding of the matrix ribbon by the ribs i is clearly visible in Fig. 5. As the-height of the ribs .8 is equal to or greater than the thickness of the ribbon to be pressed, the latter is simultaneously pressed and cut at the sides to provide a central impressed sound record portion and lateral trimmed-on portions.

What is claimed is:

1-. A process of producing sound films with mechanical sound record grooves therein, which comprises preparing a flexible ribbon-shaped masponding to the grooves to be formed and also having further ribs located laterally outside the the sound film, advancing the matrix and an impressible ribbon lengthwise and at the same rate while employing the said further ribs for guiding the matrix in its lengthwise advancing movement, said ribbon having a width greater than the spacing between said further ribs, and pressing the matrix upon the ribbon whereby to reproduce the sound track ribs of the matrix as sound track grooves in the impressible ribbon. said further ribs being eflective during the press. ing for cutting through the ribbon and separating a central impressed sound record portion from lateral trimmed-oil portions.

3. A process of producing sound fllms with mechanical sound record grooves therein, which Y comprises mechanically cutting longitudinal sound record grooves into a restricted central portion of the width of a wax layer of an original record in accordance with the sound record to be produced, cutting deep guide grooves into said wax layer at each side of the area occupied by the sound record grooves, preparing a flexible matrix from said original record having thereon ribs as the counterpart 01 said grooves, concurrently longitudinally advancing said matrix and trix having on a restricted central portion of its aw width sound track ribs corresponding to the grooves to be formed and also having further ribs located at both sides of and outside the area of the sound track ribs, said further ribs being parallel and straight when the matrix is held in flat position and being spaced apart a distance corresponding to the desired width of the sound fllm, and pressing the matrix upon an impressible ribbon whose width exceeds that ofthe spacing between said further ribs whereby to reproduce the-sound track ribs oi the matrix as sound track. grooves in the impressible' ribbon, said further ribs being effective during the pressing for cutting through the ribbon and separating a central impressed sound record portion matrix having sound track ribs thereon eorre-' an impressible blank record ribbon of width greater than the width of the desired sound film while employing the counterparts of said guide grooves for guiding the matrix during its advancement, and pressing the matrix and blank together for producing the sound record grooves in the blank and for severing a central portion as a sound film i'romv lateral trimmed-oil portions.

4. A flexible matrix for producing sound films with mechanical sound record grooves therein, comprising a ribbon-shaped member havinga plurality of sound track ribs extending along its length for a restricted central portion of the width thereof, said member also having further ribs or knife-like shape which in the flat position of the matrix extend parallel and straight along its length outside and at each side 01' said central portion for providing longitudinal guides tor handling the matrix, said further ribs being higher than the sound record ribs and providto a predetermined definite-width with the sound location thereon.

ing means for-cutting an impressible ribbon blank tracks positioned at a. predetermining definite 5. A matrix as in claim 4. in which a... further ribs are each shaped to havea'steep face at the side thereof adjacent the sound track riba 

